1. Technical Field
The present invention relates generally to an improved data processing system and in particular to an improved method and apparatus for adjusting a time generated by a clock circuit within the data processing system. Still more particularly, the present invention relates to a method and apparatus for automatic learning clock adjustment.
2. Description of the Related Art
Data processing systems contain clock generation circuits that provide a clock signal indicating a time for use in various applications. For example, the clock signal is used to provide time and date information to a user. Additionally, the clock signal is also used by applications that require an accurate time.
In general, a quartz oscillator is employed in a clock generation circuit to develop a clock signal of a pre-determined frequency for use by the data processing system. It is necessary to adjust the clock generation circuit extremely precisely to provide accurate timekeeping. This type of adjustment is generally carried out at the time of manufacture. Changes in temperature, aging of the clock generation circuit, and aging of the battery in a clock generation circuit cause variations in the oscillation of the quartz oscillator. Consequently, the accuracy of the clock generation circuit may decline over these types changes in operating conditions.
Therefore, it would be advantageous to have an improved method and apparatus for automatically adjusting a clock in response to changes in operating conditions.